Interface IGearChangeable
Abstracts the Drive/Reverse gear state so that both PlayerCarDriver and the AI path-follow system can flip gears through the same call without knowing the concrete controller implementation.
public interface IGearChangeable
Remarks
The input threshold convention (≥ 1f → Drive, ≤ −1f → Reverse) lets the
caller pass raw signed throttle without a separate gear-select step,
matching how both the player and the AI naturally produce signed speed signals.